水分管理和氮肥运筹对水稻养分吸收、转运及分配的影响

在高产施氮量180 kg hm^-2条件下，以杂交稻冈优527为材料，通过“淹水灌溉”(W₁)、“湿润灌溉(前期)+浅水灌溉(孕穗期)+干湿交替灌溉(抽穗至成熟期)”(W₂)和“旱种”(W₃) 3种灌水及不同的氮肥运筹处理，研究水分管理和氮肥运筹对水稻养分吸收、转运、分配及产量的影响，并探讨各养分间及其与产量的相互关系。结果表明，水分管理和氮肥运筹对水稻主要生育期氮、磷、钾的累积、转运、分配及产量的影响均存在显著的互作效应，水氮互作条件下各生育期氮、磷、钾间的吸收存在显著的协同效应；抽穗期氮、磷、钾的累积与各养分在结实期转运总量间，以及结实期各养分转运间均呈极显著正相关，且氮、钾在抽穗前期的累积对促进结实期各养分向籽粒的转运和提高产量影响显著，但氮肥后移比例过重(N₄处理)及W₃处理均会导致结实期叶片和茎鞘各养分转运总量的显著降低，氮、磷、钾降幅分别达2.73%~18.00%、8.03%~19.70%、6.52%~17.02%。据产量及其与养分吸收、转运间关系的表现，W₁模式下氮肥后移量以占总施氮量的40%~60%为宜，W₂模式与氮肥运筹方式为基肥:蘖肥:孕穗肥(倒四、二叶龄期分2次等量施入)=3∶3∶4组合是本试验最佳的水氮耦合运筹模式，W₃模式下，应减少氮肥的后移量，氮肥后移量占总施氮量的20%~40%为宜。

Effects of Water Management and Nitrogen Application Strategies on Nutrient Absorption, Transfer, and Distribution in Rice

Hybrid rice Gangyou 527 was used to investigate the effects of three irrigation regimes (submerged irrigation, W₁; dry cultivation, W₃; and the treatment W₂ that was damp irrigation before booting stage, shallow irrigation at booting stage, wetting-drying alternation irrigation from heading stage to mature stage) and different nitrogen (N) application ratios on absorption, transport action and distribution of N, phosphorus (P), potassium (K), and yield in rice under the high yield condition of 180 kg N ha^-1. The results showed that there was an obvious interaction between water management and N application strategies on grain yield and N, P and K absorption and transfer at the mainly growth stages. Under water-nitrogen interaction condition, there existed significantly positive correlations between the amounts of N, P and K absorption at various growth stages, and there existed highly significantly positive correlations between the accumulations of N, P, and K at heading stage and their transfer amounts during filling stage, but excess the ratio of postponed N application to the total N rate or W₃ treatment resulted in the transport amounts of N, P, and K significantly decreased during grain filling e.g. 2.73–18.00%, 8.03–19.70%, 6.52–17.02%, respectively. Furthermore, there were positive correlations between yield and the accumulations of N, P, and K with the max correlation coefficients at heading stage, mature stage, and heading stage. The accumulations of N, K before heading stage could promote nutrient transfer and yield. According to yield performance and its relationship with N, P, and K absorption characteristics, the optimum ratio of postponed N application to the total N rate was 40–60% underW₁. The N application of base (30%), tillering (30%), and panicle (40%) fertilizers equally applied at stages of 4th and 2nd leaves emerged from the top under W₂, was the best model in this paper referred to as the water-nitrogen application coupling management model. However, W₃ treatment was suitable for using 20–40% of the ratio of postponed N application to the total N application rate.